Re: [PATCH 05/18] mfd: Add support for Kontron sl28cpld management controller

From: Michael Walle
Date: Wed Mar 18 2020 - 12:38:34 EST

Am 2020-03-18 04:28, schrieb Guenter Roeck:
On 3/17/20 1:50 PM, Michael Walle wrote:
This patch adds core support for the board management controller found
on the SMARC-sAL28 board. It consists of the following functions:
- watchdog
- GPIO controller
- PWM controller
- fan sensor
- interrupt controller

At the moment, this controller is used on the Kontron SMARC-sAL28 board.

Signed-off-by: Michael Walle <michael@xxxxxxxx>
---
drivers/mfd/Kconfig | 21 ++++++
drivers/mfd/Makefile | 2 +
drivers/mfd/sl28cpld.c | 155 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 178 insertions(+)
create mode 100644 drivers/mfd/sl28cpld.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 3c547ed575e6..01588c366476 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2059,5 +2059,26 @@ config SGI_MFD_IOC3
If you have an SGI Origin, Octane, or a PCI IOC3 card,
then say Y. Otherwise say N.

+config MFD_SL28CPLD
+ tristate "Kontron sl28 core driver"
+ depends on I2C=y

Why I2C=y and not just I2C ?

Oh this should be changed in the next patch which adds
interrupt controller support, where I2C=y is needed, correct?

-michael


+ depends on OF
+ select REGMAP_I2C
+ select REGMAP_IRQ
+ select SL28CPLD_IRQ
+ select MFD_CORE
+ help
+ This option enables support for the board management controller
+ found on the Kontron sl28 CPLD. You have to select individual
+ functions, such as watchdog, GPIO, etc, under the corresponding menus
+ in order to enable them.
+
+ Currently supported boards are:
+
+ Kontron SMARC-sAL28
+
+ To compile this driver as a module, choose M here: the module will be
+ called sl28cpld.
+
endmenu
endif
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index f935d10cbf0f..9bc38863b9c7 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -259,3 +259,5 @@ obj-$(CONFIG_MFD_ROHM_BD718XX) += rohm-bd718x7.o
obj-$(CONFIG_MFD_STMFX) += stmfx.o

obj-$(CONFIG_SGI_MFD_IOC3) += ioc3.o
+
+obj-$(CONFIG_MFD_SL28CPLD) += sl28cpld.o
diff --git a/drivers/mfd/sl28cpld.c b/drivers/mfd/sl28cpld.c
new file mode 100644
index 000000000000..789f21f90752
--- /dev/null
+++ b/drivers/mfd/sl28cpld.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MFD core for the CPLD on a SMARC-sAL28 board.
+ *
+ * Copyright 2019 Kontron Europe GmbH
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+
+#define SL28CPLD_VERSION 0x03
+#define SL28CPLD_WATCHDOG_BASE 0x4
+#define SL28CPLD_HWMON_FAN_BASE 0xb
+#define SL28CPLD_PWM0_BASE 0xc
+#define SL28CPLD_PWM1_BASE 0xe
+#define SL28CPLD_GPIO0_BASE 0x10
+#define SL28CPLD_GPIO1_BASE 0x15
+#define SL28CPLD_GPO_BASE 0x1a
+#define SL28CPLD_GPI_BASE 0x1b
+#define SL28CPLD_INTC_BASE 0x1c
+
+/* all subdevices share the same IRQ */
+#define SL28CPLD_IRQ 0
+
+#define SL28CPLD_MIN_REQ_VERSION 14
+
+struct sl28cpld {
+ struct device *dev;
+ struct regmap *regmap;
+};
+
+static const struct regmap_config sl28cpld_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .reg_stride = 1,
+};
+
+static struct resource sl28cpld_watchdog_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_WATCHDOG_BASE, 1),
+};
+
+static struct resource sl28cpld_hwmon_fan_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_HWMON_FAN_BASE, 1),
+};
+
+static struct resource sl28cpld_pwm0_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_PWM0_BASE, 1),
+};
+
+static struct resource sl28cpld_pwm1_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_PWM1_BASE, 1),
+};
+
+static struct resource sl28cpld_gpio0_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_GPIO0_BASE, 1),
+ DEFINE_RES_IRQ(SL28CPLD_IRQ),
+};
+
+static struct resource sl28cpld_gpio1_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_GPIO1_BASE, 1),
+ DEFINE_RES_IRQ(SL28CPLD_IRQ),
+};
+
+static struct resource sl28cpld_gpo_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_GPO_BASE, 1),
+};
+
+static struct resource sl28cpld_gpi_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_GPI_BASE, 1),
+};
+
+static struct resource sl28cpld_intc_resources[] = {
+ DEFINE_RES_REG(SL28CPLD_INTC_BASE, 1),
+ DEFINE_RES_IRQ(SL28CPLD_IRQ),
+};
+
+static const struct mfd_cell sl28cpld_devs[] = {
+ OF_MFD_CELL("sl28cpld-wdt", sl28cpld_watchdog_resources, NULL, 0, 0,
+ "kontron,sl28cpld-wdt"),
+ OF_MFD_CELL("sl28cpld-fan", sl28cpld_hwmon_fan_resources, NULL, 0, 0,
+ "kontron,sl28cpld-fan"),
+ OF_MFD_CELL("sl28cpld-pwm", sl28cpld_pwm0_resources, NULL, 0, 0,
+ "kontron,sl28cpld-pwm"),
+ OF_MFD_CELL("sl28cpld-pwm", sl28cpld_pwm1_resources, NULL, 0, 1,
+ "kontron,sl28cpld-pwm"),
+ OF_MFD_CELL("sl28cpld-gpio", sl28cpld_gpio0_resources, NULL, 0, 0,
+ "kontron,sl28cpld-gpio"),
+ OF_MFD_CELL("sl28cpld-gpio", sl28cpld_gpio1_resources, NULL, 0, 1,
+ "kontron,sl28cpld-gpio"),
+ OF_MFD_CELL("sl28cpld-gpo", sl28cpld_gpo_resources, NULL, 0, 0,
+ "kontron,sl28cpld-gpo"),
+ OF_MFD_CELL("sl28cpld-gpi", sl28cpld_gpi_resources, NULL, 0, 0,
+ "kontron,sl28cpld-gpi"),
+ OF_MFD_CELL("sl28cpld-intc", sl28cpld_intc_resources, NULL, 0, 0,
+ "kontron,sl28cpld-intc"),
+};
+
+static int sl28cpld_probe(struct i2c_client *i2c)
+{
+ struct sl28cpld *sl28cpld;
+ struct device *dev = &i2c->dev;
+ unsigned int cpld_version;
+ int ret;
+
+ sl28cpld = devm_kzalloc(dev, sizeof(*sl28cpld), GFP_KERNEL);
+ if (!sl28cpld)
+ return -ENOMEM;
+
+ sl28cpld->regmap = devm_regmap_init_i2c(i2c, &sl28cpld_regmap_config);
+ if (IS_ERR(sl28cpld->regmap))
+ return PTR_ERR(sl28cpld->regmap);
+
+ ret = regmap_read(sl28cpld->regmap, SL28CPLD_VERSION, &cpld_version);
+ if (ret)
+ return ret;
+
+ if (cpld_version < SL28CPLD_MIN_REQ_VERSION) {
+ dev_err(dev, "unsupported CPLD version %d\n", cpld_version);
+ return -ENODEV;
+ }
+
+ sl28cpld->dev = dev;
+ i2c_set_clientdata(i2c, sl28cpld);
+
+ dev_info(dev, "successfully probed. CPLD version %d\n", cpld_version);
+
+ return devm_mfd_add_devices(dev, -1, sl28cpld_devs,
+ ARRAY_SIZE(sl28cpld_devs), NULL,
+ i2c->irq, NULL);
+}
+
+static const struct of_device_id sl28cpld_of_match[] = {
+ { .compatible = "kontron,sl28cpld", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, sl28cpld_of_match);
+
+static struct i2c_driver sl28cpld_driver = {
+ .probe_new = sl28cpld_probe,
+ .driver = {
+ .name = "sl28cpld",
+ .of_match_table = of_match_ptr(sl28cpld_of_match),
+ },
+};
+module_i2c_driver(sl28cpld_driver);
+
+MODULE_DESCRIPTION("sl28cpld MFD Core Driver");
+MODULE_LICENSE("GPL");